The invention relates to a raising chair, particularly a foldable raising wheelchair for disabled or sick persons of the type including a support frame, a seat surface, a foot rest, and/or a seat backrest, and a mechanism to raise ("erect") and lower the seat.
Different raising chairs are known which are capable to move a disabled person, e.g. a paraplegic patient, from a sitting position into an extended, near-vertical, erect, standing position. The advantages of such a raising chair for patients are generally recognized. Repeated raising and sitting contributes to blood circulation. Of medical importance is the possibility of daily standing exercises without the need of help or special equipment. This diminishes the susceptibility for decubitus and osteoporosis. Of practical importance is also the increased independence of the person and the improved possibility of professional integration provided by increased mobility. Of psychological importance is further that a raising chair gives the patient increased self confidene and the same eye-level with a standing person in conversation.
A prior-art raising chair is described in the U.S. Pat. No. 3,589,769. In this prior-art raising chair, the seat surface member and the seat backrest comprise a plurality of padded rollers. It must be noted that in prior-art raising chairs a relative motion occurs on a raising or lowering motion between the patient and the surfaces of the chair on which the body of the patient rests. To facilitate this "gliding" motion, the cited prior-art chair has a seat and a backrest in form of rollers. This facilitates the change of the patient from the seating position to the erected position, and vice versa. However, this design is found uncomfortable by the patient after prolonged sitting. Because the body is not evenly supported, stagnations of blood may occur which may be unhealthy or even dangerous for the patient.
It is an object of the present invention to avoid the disadvantages of prior-art raising chairs.